08-27-周三_17-09-29

node_modules/dagre-d3-renderer/lib/intersect/intersect-rect.js

@@ -0,0 +1,32 @@
+function intersectRect (node, point) {
+  const x = node.x
+  const y = node.y
+
+  // Rectangle intersection algorithm from:
+  // http://math.stackexchange.com/questions/108113/find-edge-between-two-boxes
+  const dx = point.x - x
+  const dy = point.y - y
+  let w = node.width / 2
+  let h = node.height / 2
+
+  let sx, sy
+  if (Math.abs(dy) * w > Math.abs(dx) * h) {
+    // Intersection is top or bottom of rect.
+    if (dy < 0) {
+      h = -h
+    }
+    sx = dy === 0 ? 0 : h * dx / dy
+    sy = h
+  } else {
+    // Intersection is left or right of rect.
+    if (dx < 0) {
+      w = -w
+    }
+    sx = w
+    sy = dx === 0 ? 0 : w * dy / dx
+  }
+
+  return {x: x + sx, y: y + sy}
+}
+
+export default intersectRect